Seismic surveys utilize acoustic reflections from stratigraphic interfaces, fractures, and other anomalies to generate seismic maps that display subsurface stratigraphic interfaces, known as horizons, fractures, lineations and other anomalies.
In structural geology lithological lineations are identified as linear structural features within rocks, which may include a fault, a fracture corridor, a change in the rock lithology, or some other geological discontinuity. There are several types of lithological lineations, such as intersection lineations, crenulation lineations, mineral lineations and stretching lineations being the most common.
Intersection lineations may be formed be due to the intersection of two foliations and stretching lineations may be formed by shearing of rocks during asymmetric deformation of a rock mass.
Intersecting and stretching lineations may be measured on a single outcrop, and may typically have lengths of several millimeters to several meters.
Lineations mapped on seismic volumes, on the other hand, may typically be measured on several outcrops and may have lengths of several hundred to several thousand meters.
U.S. Pat. No. 4,228,529 discloses a method for enhancing display of natural lithological lineations in a seismic map by applying shading patterns to zones between contour segments. This known lineation display enhancement method may still have an insufficient resolution to display minor lineations generated by subtle structural geological features.
There is a need for an improved method for displaying lithological and structural lineations with an enhanced resolution such that also minor lineations generated by subtle structural geological features are accurately displayed in a seismic map.